Wall construction for heaters



Nov. 27, 1945.

w. c. HENsEL WALL CONSTRUCTION FOR HEATERS Filed April 21, 1941 Patented Nov. 27, 1945 WALL CONSTRUCTION FOR HEATERS Walter C. Hensel, Chicago, lll., assigner to Universal Oil Products Company, Chicago, Ill., a

corporation of Delaware Application April 21, 1941, Serial No. 389,553

(Cl. l2-101) :somma This is a. continuation-impart of my co-pending application Serial Number 271,901, filed May 5, 1939, now Patent Number 2,270,297.

The invention is particularly directed to an improved form of wall construction for heaters, furnaces, ovens and the like employing preformed blocks or slabs of insulating and refractory materials which are suspended from an outer structural framework.. The invention also embraces preformed slabs or blocks of a form adapted for use in such walls.

The improved construction provided makes the use of light weight preformed slabs of refractory and insulating material both practical and highly advantageous. It permits rapid and accurate assembly of the walls of heaters and the like with a minimum of expensive field labor and results in a light weight wall of good refractory characteristics and low heat conductivity.

The invention is not limited to noiis novelty claimed herein for any specic composition of insulating refractory slab or block. It is concerned primarily with the form of construction of said blocks and the means whereby they are secured to the structural framework of the heater. Slabs or blocks of various compositions which possess both refractory and insulating character-` istics are now available. In some of these the insulating and refractory qualities are combined in a single material, while others comprisea substantial thickness of insulating material surfaced on one side'with a relatively thin layer of good refractory material. The features of the invention are applicable to and advantageous as applied to either type.

One type of insulating refractory slab, to which the features of the invention are applicable, comprises granules of refractory material, such as fire-clay, crushed fire-brick or the like, held together by a suitable binder with a relatively large volume of small air pockets or voids within the mass. These air pockets or voids are created by incorporating a readily combustible or vaporizable material, such as, for example, ground cork, vegetable or wood fibers, solid naphthalene particles or the like in a mixture of refractory material and binder from which the slab is`formed, the volatile or combustible material being burned or proofed on its cold side by the application of asphalt or the like.

Another type of slab or block which is suitable wool, exfoliated vermlculite or the like, preferably somewhathcompressed and held together with a suitable binder, such as high alumina ce- Vment; emulsified asphalt, sodium silicate or the like and surfaced on one side with a relatively thin layer of refractory material which isapplied in semi-fluid or plastic state and bonded to the insulating material, the slab being dried or cured to the desired degree after it is formed and before it is placed in service.

The invention provides a metal backing or reinforcing for slabs of the general character above mentioned which serves to stiffen the same and facilitate their transportation and handling without breakage. In the preferred embodiment of the invention, this metal backing comprises a screen of the type generally known as expanded metal lath and I prefer to employ the diamond mesh type of this material. It is secured to the insulating refractory slab on or adjacent 'the cold surface of the latter (that opposite the surface to which heat is applied in service) by portions of the metal backing which are bent outwardly from theA surface thereof and embedded in the slab.'

jecting portions which are embedded in the slab are of such form that a definite mechanical bond y or key is secured between the main body of the evaporated from the. formed slab before it is placed in service. The slab may be surfaced,when desired, on the side towhich heat is applied with aslurry of fire-clay or other suitable refractory material to provide a more homogeneous and less porous surface and, when desired, may begwater-l -in substantial alignment.v

slab and the metal backing. l

A substantially V-shaped rib of relatively light gauge metal is secured to the metal backing by welding or in any other convenient manner, the ribs being disposed in substantially parallel spaced apart relationship on the slab and protruding outwardly therefrom. These ribs are notched at their ends which terminate approximately at the edges of the slabs.

In assembling the wall, the slabs are substantially abutted along their edges, preferably with a suitable seal, such as plastic cementitious .material, disposed therebetween, and with the ribs Suitable metal clips are provided which engage the notches in the adjacent endsof the ribs in dilferent slabs, these `clips being also engaged with suitable metal stringers or studs which form a part of a structural framework supporting the walls of the heater.

The features of the invention will be more clearly understood by reference to the accompanying diagrammatic drawing and the following description thereof.

In the drawing Figs. 1, 2 and 3 are, respectively, an elevational view, a side view and an end view of a diamond mesh metal backing provided by the invention for attachment to an insulating refractory slab or block.

Fig. 4 is a view in perspective of a portion of a wall employing insulating refractory slabs constructed and attached to a metal framework in accordance with the features of the invention.

Fig. 5 is a cross-sectional view of a portion of a heater showing a vertical wall and a sloping wall constructed in accordance with the features of the invention.

Referring to the drawing, a sheet of diamond mesh, expanded metal lath, indicated by the reference numeral I, is cut to the approximate size of the slab to be formed and at spaced points throughout the sheet two adjacent legs, whichv form the bottom of the diamond mesh, are severed and the thus freed portion of the mesh is bent back at substantially right angles to the face of the sheet, as indicated at 2 in Figs. 2 and 3.

The V-shaped ribs 3 are formed` of fairly light gauge sheet steel or other suitable metal and the legs 4 of these members are secured by spot welding, wiring or in any other convenient manner to the sheet I so that the v-shaped portion protrudes a substantial distance from the face of the sheet. The ribs 3 are notched, top and bottom, as indicated at 5 in Fig. 3, to receive the attaching clips 6 (see Figs. 4 and 5). I

'Ihe insulating material 1 of the slab or'block is applied to the sheet of reenforcing mesh usually by placing the mesh in the bottom of a suitable form, not shown, with the portions 2 extending upward, and the insulating material with a suitable binder is placed in the mold above the mesh in relatively plastic state and preferably is slightly compressed to the desired thickness, suchcompression being suilcient to obtain good contact between the insulating material and the binder and toengage the insulating material with or key it to the mesh. The refractory material and binder which forms the surface coating 8 of the slab is applied over the insulating material and it is also preferably compressed slightly to obtain good contact between the same and the surface of the insulating material so that the two will be rmly bonded. After the slab has dried suiilciently to permit its removal from the form or mold, it is removed and further dried or cured and is then ready for use.

In erecting a wall employing the slabs, a suitable framework of structural steel, a portionof which is indicated at 9 in Fig. 5, is erected with suitable stringers I secured to and extending between adjacent spaced members 9 of the framework. The stringers I0, in the case here illus? trated, are steel angles with one legupstanding, spaced from and substantially parallel to` the members 9, the other leg being secured to the members 9 by meansof clip angles Il, employing bolting, riveting or any other convenient means of attachment.

To attach the slabs to the framework, suitable metal clips which may, for example, be iron or malleable castings, are slipped over' the upstanding legs of members Ill, as illustrated, and the recesses in the' ends of the ribs 3 of the slabs are engaged with the lugs I2 of the clips, which, together with that portion of the clip extending at substantially right angles from the upstanding leg of members Il, forms a Tshaped section. At corners of the structure, such as indicated at I3, for example in Fig. 5, the edges of the adjoining slabs are formed or cut at a suitable angle and the lugs of the attaching clips 6', at this point are correspondingly formed or bent at the desired angle.

Preferably, a suitable cementitious material, such as fire clay, furnace cement or the like, indicated at Il in Figs. 4 and 5, is placed between the edges of the adjoining slabs as the latter are placed in the wall to seal the joints between the slabs and .prevent leakage of air or combustion products through the wall,

For exterior construction, the slabs may be surfaced on the cold side (opposite the refractory facing) with asphalt or the like to render them water-resistant and/or, when desired, a suitable sheet metal housing may be provided and will usually take the form of steel sheets secured to the outer flanges of members 9, as indicated, for example, at l5 in Fig. 5.

It will be apparent from th'e drawing and above description that it exemplifies only one of the many specific forms of slabs embodying the features of the invention and only one of the many specific manners in which they may be secured to a metal framework, and that the features of the invention provide a fire-resistant wall suitable for use in furnaces, heaters and the like which may be easily and quickly erected with a minimum of field labor and which is adaptable to a wide variety of structures of the class mentioned. It will, of course, be understood thatv the slabs may be suspended from structural framework in a horizontal as Well as in vertical or inclined planes and the term wall esem-- ployed in the appended claims is, therefore, in-

tended to include roofs, oors and the like as well as side walls.

I claim as my invention:

1. A wall slab for heaters and the like comprising a substantial thickness of insulating material, a lesser thickness of refractory1 material consisting of a set plastic mixture disposed over one surface of the insulating material and directly bonded thereto in setting and a sheet of open-work metal disposed adjacent and substantially co-extensive with the opposite face thereof and secured to the insulating material by spaced anchoring means integral with said sheet and projecting from the plane thereof into the insulating material for a distance substantially less than the thickness of the latter.

2. lAn. integral preformed wall slab adapted for use in furnaces, heaters and the like and comprising, in combination, a substantial thickness of heat insulating material, a relatively thin layer of denser refractory material covering said insulating material and constituting one face of the slab, said refractory material being a set plastic mixture which, in setting, is directly bonded to theinsulating material and is supported by metal sheet provided with spaced stiening ribs.

thereon which project outwardly, from the plane of the sheet and from the adjacent face of the slab.

assenza l 3. A slab such as defined in. claim 2, wherein said ribs are provided with openings therein adapted to receive clips for attaching the slab to a supporting metal framework for said wall.

i. An integral, preformed Wall slab adapted for use in furnaces, heaters, and the like and comprising, in combination, a substantial thickness of heat insulating material, a layer of denser refractory material, sumciently thin to be sup--I ported by said, insulating material and disposed over the inner face of the slab said refractory material being a. set plasic mixture which, in setting, is directly bonded to the insulating material, reeniorcing means comprising a mesh-like sheet of expanded metal disposed adjacent the opposite, outer face of the slab and secured to the E5, Work ior said wall.

insulating material by spaced portions of its mesh partially detached and bent inwardly from the plane of said sheet to extend into the insulating material for a distance substantially less than the thickness of the latter, whereby a substantial thickness of the insulating material separates said metal reenforcing means from said refractory face of the slab.

' 5. A slab such as deined in claim i, wherein spaced stifening ribs are provided on said reenforcing sheet, said ribs projecting from said adjacent outer face of the slab and being provided with openings therein adapted to receive clips for attaching the slab to a supporting metal frame- VVALTER C. HENSEL. 

